CN102998083B - The method of the actual wind load of platform is obtained by self-elevating drilling platform wind tunnel test - Google Patents

Abstract

The invention discloses a kind of method being obtained the actual wind load of platform by self-elevating drilling platform wind tunnel test, cardinal principle of the present invention be wind tunnel test is divided into waterborne and under water two parts carry out, test findings provides waterborne under each wind direction angle and two-part data result under water respectively with nondimensional form, comprises the dimensionless factor of force and moment in level, longitudinal direction, vertical three directions.Use this method to analyze all self-elevating drilling platforms or similar platform wind tunnel test, process is very easy, substantially increases work efficiency.The present invention, by by determining fast self-elevating platform (SEP) wind heeling moment, can improve the efficiency of stability analysis, saves cost.

Description

The method of the actual wind load of platform is obtained by self-elevating drilling platform wind tunnel test

Technical field

The present invention relates to a kind of marine engineering design field, more particularly, relate to the determination of the drilling platform wind load for stability analysis.

Background technology

Obtain primarily of two kinds of methods for wind heeling moment: proper calculation and wind tunnel test.Whether each classification society rule in the detail property of there are differences for wind load computing formula, such as, considers impact meeting and the calculated case difference to some extent of the many factors such as capture-effect, turbulent flow, boundary layer, need take into account device structure the level of detail etc. of wind load.In addition, the wind load calculated according to the coefficient of modular formula and recommendation, the same yardstick self-elevating platform (SEP) product of contrast design abroad company, obviously higher.

As shown in Figure 2, be schematic diagram waterborne, stressed when platform is in free drifting state under water.D in figure _awfor above water is stressed, D _uwfor underwater portion is stressed, H _awfor the above water arm of force, H _uwfor the underwater portion arm of force, M _tfor the total wind heeling moment of platform according to above-mentioned parameter conversion gained.

For self-elevating drilling platform, the impact of wind load on platform is greater than the impact of wave and ocean current.Under towage operating mode, the motion of self-elevating drilling platform is comparatively complicated, and its load suffered mainly contains inertial load that Platform movement causes, deadweight and wind load etc.About occupying 40% ~ 50% of self-elevating platform (SEP) environmental load according to the wind load that modular formula calculates, is the important performance affecting parameters of self-elevating platform (SEP) stability and structural strength.Visible, comparatively reasonably determining the wind load of drilling platform, is the task of top priority to deep-water developments of drilling platform optimal design and platform.

Summary of the invention

The present invention is method self-elevating drilling platform results of wind tunnel being applied to real ship.By by determining fast self-elevating platform (SEP) wind heeling moment, the efficiency of stability analysis can be improved, save cost.

In order to achieve the above object, the invention provides a kind of method being obtained the actual wind load of platform by self-elevating drilling platform wind tunnel test, comprise the steps:

S1, be self-elevating drilling platform setting coordinate system, flat surface is XY plane, and vertical described flat surface is Z axis;

S2, design, measurement, and obtain data by wind tunnel test, and obtain parameter with following a-f formula:

Wind tunnel test be divided into waterborne and under water two parts carry out, test findings provides waterborne under wind angle ψ and two-part data result under water respectively with nondimensional form, comprise the dimensionless factor of force and moment in level, longitudinal direction, vertical three directions, be denoted as follows respectively:

A) longitudinal force coefficient: $X^{\′}=\frac{X}{1/2\·\mathrm{\ρ}{U}^2{L}_{\mathrm{PP}}^2}$

B) cornering ratio: $Y^{\′}=\frac{Y}{1/2\·\mathrm{\ρ}{U}^2{L}_{\mathrm{PP}}^2}$

C) vertical force coefficient: $Z^{\′}=\frac{Z}{1/2\·\mathrm{\ρ}{U}^2{L}_{\mathrm{PP}}^2}$

D) heeling moment coefficient: $K^{\′}=\frac{K}{1/2\·\mathrm{\ρ}{U}^2{L}_{\mathrm{PP}}^3}$

E) Trimming Moment coefficient: $M^{\′}=\frac{M}{1/2\·\mathrm{\ρ}{U}^2{L}_{\mathrm{PP}}^3}$

F) torque coefficient: $N^{\′}=\frac{N}{1/2\·\mathrm{\ρ}{U}^2{L}_{\mathrm{PP}}^3}$

Wherein symbol description and unit as follows

Wherein, the arm of force should from total wind-engaging surface pressing center to the vertical gauge of this platform underwater case center of lateral resistance; And the centre of draft of underwater portion is taken as the half of drinking water;

Calculate acquisition parameter to comprise: the parameter according to design or mensuration calculates platform parameter X' waterborne _aw, Y _a' _w, K' _aw, M' _aw, and platform parameter X' under water _uw, Y _u' _w, K' _uw, M' _uw;

Test obtains parameter and comprises: Z' _aw, N' _aw, Z' _uw;

Wherein, subscript aw is parameter waterborne, and subscript uw is parameter under water;

S3, the data utilizing S2 to obtain, according to following formula, wind heeling moment M corresponding under obtaining described wind angle ψ _t:

Above water wind is gone all out arm H _aw, unit is m:

$H_{\mathrm{aw}}=\frac{-K_{\mathrm{aw}}^{\′}\·\sin (180-\mathrm{\ψ})+M_{\mathrm{aw}}^{\′}\·\cos (180-\mathrm{\ψ})}{X_{\mathrm{aw}}^{\′}\·\cos (180-\mathrm{\ψ})+Y_{\mathrm{aw}}^{\′}\·\sin (180-\mathrm{\ψ})}{L}_{\mathrm{pp}}$

Underwater portion wind is gone all out arm H _uw, unit is m:

$H_{\mathrm{uw}}=\frac{-K_{\mathrm{uw}}^{\′}\·\sin (-\mathrm{\ψ})+M_{\mathrm{uw}}^{\′}\·\cos (-\mathrm{\ψ})}{X_{\mathrm{uw}}^{\′}\·\cos (-\mathrm{\ψ})+Y_{\mathrm{uw}}^{\′}\·\sin (-\mathrm{\ψ})}{L}_{\mathrm{pp}}$

Waterborne stressed, i.e. wind-force D _aw, unit is N:

D _aw＝X _aw·cos(180-ψ)+Y _aw·sin(180-ψ)

Stressed D under water _uw, unit is N:

D _uw＝X _uw·cos(-ψ)+Y _uw·sin(-ψ)

The wind heeling moment M that platform is total _t, unit is Nm:

M _t＝(|H _aw|+H _uw)·D _aw

S4, given various wind angle ψ, repeat S2-S3 and obtain corresponding wind heeling moment M _t.

By above-mentioned steps, the wind heeling moment M that the various wind angle ψ that step S4 can be obtained are corresponding _tfor stability analysis.

The present invention relates to a kind of method that self-elevating drilling platform results of wind tunnel is applied to the actual wind load of platform, its cardinal principle be wind tunnel test be divided into waterborne and under water two parts carry out, test findings provides waterborne under each wind direction angle and two-part data result under water respectively with nondimensional form, comprises the dimensionless factor of force and moment in level, longitudinal direction, vertical three directions.Use this method to analyze all self-elevating drilling platforms or similar platform wind tunnel test, process is very easy, substantially increases work efficiency.

Accompanying drawing explanation

Fig. 1 is wind tunnel test coordinate schematic diagram;

Fig. 2 is the schematic diagram waterborne, stressed under water when being in free drifting state of platform.

Embodiment

The present invention is method self-elevating drilling platform results of wind tunnel being applied to the actual wind load of platform, by self-elevating drilling platform results of wind tunnel being applied to the method for the actual wind load of platform, obtain required wind heeling moment value when actual platform calculates stability fast.Specifically, the wind load numerical value of actual platform is obtained by testing the level of the platform above water that records and underwater portion, longitudinal direction, the dimensionless factor of force and moment in vertical three directions and relevant reduction formula.Detailed process of the present invention is as follows:

As shown in Figure 1, be self-elevating drilling platform setting coordinate system, flat surface is XY plane, and vertical described flat surface is Z axis.ψ is wind angle, and TRIM is platform inclination direction, and K, M, N are respectively the moment that platform corresponds to X-axis, Y-axis, Z axis under wind-force effect.Wind tunnel test be divided into waterborne and under water two parts carry out, test findings provides waterborne under each wind direction angle and two-part data result under water respectively with nondimensional form, comprise the dimensionless factor of force and moment in level, longitudinal direction, vertical three directions, be denoted as follows respectively:

A) longitudinal force coefficient: $X^{\′}=\frac{X}{1/2\·\mathrm{\ρ}{U}^2{L}_{\mathrm{PP}}^2}$

B) cornering ratio: $Y^{\′}=\frac{Y}{1/2\·\mathrm{\ρ}{U}^2{L}_{\mathrm{PP}}^2}$

C) vertical force coefficient: $Z^{\′}=\frac{Z}{1/2\·\mathrm{\ρ}{U}^2{L}_{\mathrm{PP}}^2}$

D) heeling moment coefficient: $K^{\′}=\frac{K}{1/2\·\mathrm{\ρ}{U}^2{L}_{\mathrm{PP}}^3}$

E) Trimming Moment coefficient: $M^{\′}=\frac{M}{1/2\·\mathrm{\ρ}{U}^2{L}_{\mathrm{PP}}^3}$

F) torque coefficient: $N^{\′}=\frac{N}{1/2\·\mathrm{\ρ}{U}^2{L}_{\mathrm{PP}}^3}$

In formula, symbolic interpretation is in table 1.

Table 1 symbol description and unit

According to code requirement, when wind heeling moment calculates, its arm of force should from total wind-engaging surface pressing center to the vertical gauge of this platform underwater case center of lateral resistance.When adopting the wind load based on formula, the centre of draft of underwater portion is taken as the half of drinking water.Use wind tunnel test data, the wind calculating above water and underwater portion is respectively gone all out arm, then determines total wind heeling moment according to the wind load size of actual measurement.

X ' for calculating in following formula _aw, Y ' _aw, K ' _aw, M ' _awfor platform parameter waterborne, X ' _uw, Y ' _uw, K ' _uw, M ' _uwfor platform parameter under water, test the Z ' obtained _aw, N ' _aw, Z ' _uw, N ' _uwonly for reference, do not participate in wind heeling moment and calculate, ψ represents wind direction angle.

The concrete grammar that self-elevating drilling platform results of wind tunnel is converted to real ship is as follows:

Above water wind is gone all out arm H _aw, unit is m:

$H_{\mathrm{aw}}=\frac{-K_{\mathrm{aw}}^{\′}\·\sin (180-\mathrm{\ψ})+M_{\mathrm{aw}}^{\′}\·\cos (180-\mathrm{\ψ})}{X_{\mathrm{aw}}^{\′}\·\cos (180-\mathrm{\ψ})+Y_{\mathrm{aw}}^{\′}\·\sin (180-\mathrm{\ψ})}{L}_{\mathrm{pp}}$

Underwater portion wind is gone all out arm H _uw, unit is m:

$H_{\mathrm{uw}}=\frac{-K_{\mathrm{uw}}^{\′}\·\sin (-\mathrm{\ψ})+M_{\mathrm{uw}}^{\′}\·\cos (-\mathrm{\ψ})}{X_{\mathrm{uw}}^{\′}\·\cos (-\mathrm{\ψ})+Y_{\mathrm{uw}}^{\′}\·\sin (-\mathrm{\ψ})}{L}_{\mathrm{pp}}$

Waterborne stressed, i.e. wind-force D _aw, unit is N:

D _aw＝X _aw·cos(180-ψ)+Y _aw·sin(180-ψ)

Stressed D under water _uw, unit is N:

D _uw＝X _uw·cos(-ψ)+Y _uw·sin(-ψ)

The wind heeling moment M that platform is total _t, unit is Nm:

M _t＝(|H _aw|+H _uw)·D _aw

Conversion obtains the different wind heeling moment M of the correspondence under each different position angle wind angle ψ _tafter, namely can be used as input data and platform stability is calculated.

Preferred embodiment: be that example describes the present invention below in conjunction with certain platform.

Test findings provides waterborne under each wind direction angle and two-part data result under water respectively with nondimensional form, and comprise the dimensionless factor of force and moment in level, longitudinal direction, vertical three directions, result is as follows:

Above water result:

Ψ	X'	Y'	Z'	K'	M'	N'
							[°]	[-]	[-]	[-]	[-]	[-]	[-]
0	-0.9074	0.0124	-0.2264	0.0020	0.8032	0.0200
							10	-0.8965	0.2134	-0.2399	0.1586	0.7963	0.0188
20	-0.8340	0.3888	-0.2456	0.2900	0.7318	0.0122
							30	-0.7428	0.5488	-0.2641	0.4110	0.6525	0.0056
40	-0.6850	0.7169	-0.2892	0.5303	0.6041	0.0042
							50	-0.6039	0.8492	-0.3011	0.6076	0.5438	0.0040

Underwater portion result:

Ψ	X'	Y'	Z'	K'	M'	N'
							[°]	[-]	[-]	[-]	[-]	[-]	[-]
0	0.0717	0.0000	0.1386	0.0000	0.0340	0.0000
							10	0.0699	-0.0072	0.1355	-0.0006	0.0329	-0.0002
20	0.0641	-0.0143	0.1275	-0.0003	0.0304	-0.0006
							30	0.0571	-0.0225	0.1176	0.0012	0.0255	0.0001
40	0.0464	-0.0291	0.1072	0.0037	0.0211	0.0004
							50	0.0384	-0.0355	0.1039	0.0076	0.0134	0.0002

To convert the wind tunnel obtained according to above water result:

Ψ	Xaw	Yaw	Daw	Kaw	Maw	Haw
							[°]	[N]	[N]	[N]	[Nm]	[Nm]	[m]
0	-3796736	51884	3796736	607963	244157983	64.3
							10	-3751128	892907	3849192	48211474	242060510	64.1
20	-3489616	1626814	3835570	88154650	222453700	62.4
							30	-3108018	2296285	3839765	124936418	198347963	61.0
40	-2866172	2999647	4123751	161201417	183635256	59.2
							50	-2526834	3553216	4346139	184699191	165305168	57.0

To convert the wind tunnel obtained according to underwater portion result:

Ψ	Xuw	Yuw	Duw	Kuw	Muw	Huw
							[°]	[N]	[N]	[N]	[Nm]	[Nm]	[m]
0	300007	0	300007	0	10335373	34.5
							10	292475	-30126	293263	-182389	10000993	33.5
20	268207	-59834	272496	-91194	9241039	31.8
							30	238917	-94144	253981	364778	7751530	27.1
40	194147	-121760	226991	1124732	6414011	24.8
							50	160673	-148539	217066	2310260	4073353	20.2

Then to convert the wind heeling moment obtained suffered by platform according to above wind tunnel:

Ψ	Mt
		[°]	[tm]
0	38222.0
		10	38288.7
20	36797.1
		30	34504.6
40	35340.2
		50	34210.3

Had above result, namely can be used as input data can calculate platform stability.

The above; be only the present invention's preferably embodiment; but protection scope of the present invention is not limited thereto; anyly be familiar with those skilled in the art in the technical scope that the present invention discloses; be equal to according to technical scheme of the present invention and inventive concept thereof and replace or change, all should be encompassed within protection scope of the present invention.

Claims (2)

1. obtained a method for the actual wind load of platform by self-elevating drilling platform wind tunnel test, it is characterized in that, comprise the steps:

S1, be self-elevating drilling platform setting coordinate system, flat surface is XY plane, and vertical described flat surface is Z axis;

S2, design, measurement, and obtain data by wind tunnel test, and with following a)-f) formula acquisition parameter:

Wind tunnel test be divided into waterborne and under water two parts carry out, test findings provides waterborne under wind angle ψ and two-part data result under water respectively with nondimensional form, comprise the dimensionless factor of force and moment in level, longitudinal direction, vertical three directions, be denoted as follows respectively:

A) longitudinal force coefficient: $X^{\′}=\frac{X}{1/2\·{\mathrm{\ρU}}^2{L}_{PP}^2}$

B) cornering ratio: $Y^{\′}=\frac{Y}{1/2\·{\mathrm{\ρU}}^2{L}_{PP}^2}$

C) vertical force coefficient: $Z^{\′}=\frac{Z}{1/2\·{\mathrm{\ρU}}^2{L}_{PP}^2}$

D) heeling moment coefficient: $K^{\′}=\frac{K}{1/2\·{\mathrm{\ρU}}^2{L}_{PP}^3}$

E) Trimming Moment coefficient: $M^{\′}=\frac{M}{1/2\·{\mathrm{\ρU}}^2{L}_{PP}^3}$

F) torque coefficient: $N^{\′}=\frac{N}{1/2\·{\mathrm{\ρU}}^2{L}_{PP}^3}$

Wherein:

X-longitudinal force, the i.e. power of X-direction, Chinese unit is newton, and English unit is N;

Y-transverse force, the i.e. power of Y-direction, Chinese unit is newton, and English unit is N;

Z-vertical force, the i.e. power of Z-direction, Chinese unit is newton, and English unit is N;

K-heeling moment, namely around the moment of X-axis, Chinese units Newtons rice, English unit Nm;

M-Trimming Moment, namely around the moment of Y-axis, Chinese units Newtons rice, English unit Nm;

N-moment of torsion, namely around the moment of Z axis, Chinese units Newtons rice, English unit Nm;

ρ-air specific weight=1.21, Chinese unit kg/m ³, English units/kg/m ³;

U-wind speed, Chinese unit meter per second, English unit m/s;

L _pp-main hull length, Chinese unit rice, English unit m;

In addition, the arm of force should from total wind-engaging surface pressing center to the vertical gauge of this platform underwater case center of lateral resistance; And the centre of draft of underwater portion is taken as the half of drinking water;

Calculate acquisition parameter to comprise: the parameter according to design or mensuration calculates platform parameter X' waterborne _aw, Y ' _aw, K ' _aw, M' _aw, and platform parameter X' under water _uw, Y ' _uw, K' _uw, M' _uw;

Test obtains parameter and comprises: Z' _aw, N' _aw, Z' _uw;

Wherein, subscript aw is parameter waterborne, and subscript uw is parameter under water;

S3, the data utilizing S2 to obtain, according to following formula, wind heeling moment M corresponding under obtaining described wind angle ψ _t:

Above water wind is gone all out arm H _aw, unit is m:

$H_{aw}=\frac{-K_{aw}^{\′}\·sin(180-\mathrm{\ψ})+M_{aw}^{\′}\·cos(180-\mathrm{\ψ})}{X_{aw}^{\′}\·cos(180-\mathrm{\ψ})+Y_{aw}^{\′}\·sin(180-\mathrm{\ψ})}{L}_{pp}$

Underwater portion wind is gone all out arm H _uw, unit is m:

$H_{uw}=\frac{-K_{uw}^{\′}\·\sin \left(-\mathrm{\ψ}\right)+M_{uw}^{\′}\·\cos \left(-\mathrm{\ψ}\right)}{X_{uw}^{\′}\·\cos \left(-\mathrm{\ψ}\right)+Y_{uw}^{\′}\·\sin \left(-\mathrm{\ψ}\right)}{L}_{pp}$

Waterborne stressed, i.e. wind-force D _aw, unit is N:

D _aw＝X _aw·cos(180-ψ)+Y _aw·sin(180-ψ)

Stressed D under water _uw, unit is N:

D _uw＝X _uw·cos(-ψ)+Y _uw·sin(-ψ)

The wind heeling moment M that platform is total _t, unit is Nm:

M _t＝(|H _aw|+H _uw)·D _aw

S4, given various wind angle ψ, repeat S2-S3 and obtain corresponding wind heeling moment M _t.

2. obtained the method for the actual wind load of platform according to claim 1 by self-elevating drilling platform wind tunnel test, it is characterized in that, the wind heeling moment M that the various wind angle ψ obtained by step S4 are corresponding _tfor stability analysis.